If You Do One Healthy Thing Today, Do This: SMILE

According to a new study, having a positive attitude can go a long way—in life in general, and even in your workouts. Researchers found that subjects who felt "powerless" were more likely to estimate the weights of boxes they had to pick up as being much heavier than they really were. Those who had a more positive attitude—who felt like they had some power in the world and in their lives—estimated the boxes' weight as much lighter. Worth it to at least try to grin at your next workout, right?

Of course, when you're not in a shiny-happy mood, it can be hard to muster up a smile. Lately, this squirrel trying to bury a nut in a dog's coat has done wonders for my mood (look at his tiny tapping paws!):